1. Field of the Invention
The present invention relates to an ink jet recording head and, more particularly, to an ink jet recording head used in an ink jet recording system for forming flying ink droplets.
2. Description of the Prior Art
An ink jet recording head applied to an ink jet recording system comprises small discharging ports (orifices), ink channels, an intermediate liquid chamber for storing the ink and an energy generating portion provided in a part of each of the ink channels.
A method of forming an ink channel which comprises the steps of forming small grooves on a glass or metal plate by cutting or etching and thereafter bonding the plate to another plate, is a known a method of making such an ink jet recording head.
However, in the head formed by the conventional method described above, an inner wall of the ink channel of the head may be excessively roughened, or the ink channel of the head may be distorted due to an etching rate variation. Therefore, it is difficult to form the ink channel high precision, and the resultant ink jet recording head tends to produce variations in the ink discharge characteristics. Further, cracks and damage tend to occur in the plate during cutting, thereby decreasing the yield of ink jet recording heads. In particular, when etching is performed, the many manufacturing steps increase the manufacturing cost, resulting in inconvenience. In addition to this disadvantage, a common drawback of the conventional methods lies in the fact that it is difficult to properly align a grooved plate having a groove for an ink channel with a cover plate having active elements such as heater elements and piezoelectric elements for generating energy to be applied to the ink. As a result, mass production cannot be effectively performed.
In order to overcome these problems, a method of manufacturing an ink jet recording head is disclosed in German Laid-open Patent Application DOLS No. 3108206. (corresponding to Japanese Patent Application Laid-Open No. 57-43876) wherein an ink channel wall made of a hardened film of photo-sensitive resin is formed on a substrate having energy generating elements disposed thereon, and thereafter a cover is disposed to cover the ink channel.
The ink jet recording head having the ink channel wall of the photo-sensitive resin film has advantages in that the ink channel surfaces are smoothed to a high precision, the manufacturing steps become simplified, and the product yield is increased.
However, in this ink jet recording head, it is difficult to align the components of the ink jet recording head therebetween, especially members constituting an intermediate ink chamber for supplying an ink to an orifice through the ink channel. This alignment work requires great skill. In addition to this disadvantage, when the substrate and the constituent members of the ink jet recording head are bonded together, an adhesive flows in the ink jet channel, which then becomes clogged. The obviation of these problems is required because an ink jet recording head with high density multi-orifices and uniformly high performance capable of recording the high resolusion images is recently required.